1. Field of the Invention
The present invention relates to an image scaling device and method and, more particularly, to an image scaling device and method for scaling two-dimensional image.
2. Description of the Related Art
Generally, an analog image signal (analog signal) received by the television and personal computer needs to be converted by an analog/digital converter (changing to a digital signal) and then be processed by an image processor to generate a digital image signal for output to a display device of the television or personal computer. However, the resolution (such as 640×480) of the analog image signal may differ from the resolution (such as 800×600) of the digital image signal displayed on the display device, or the resolution of the digital image signal may need to be adjusted due to a size difference of the display device (for example, a aspect ratio is changed from 4:3 to 16:9).
As shown in FIG. 1, U.S. Pat. No. 5,739,867, entitled “Method and apparatus for upscaling an image in both horizontal and vertical directions” discloses an image upscaling device 10, which comprises: an input data synchronizer 11, a line buffer 12, a FIFO 13, an interpolation line buffer 14, a vertical interpolator 15 and a horizontal interpolator 16, wherein a working frequency of the input data synchronizer 11 is named I-CLK; a working frequency of the line buffer 12, the FIFO 13, the interpolation line buffer 14, the vertical interpolator 15 and the horizontal interpolator 16 is named S-CLK; and the line buffer 12 receives image with the working frequency I-CLK in order to communicate with the input data synchronizer 11, and outputs image with the working frequency S-CLK in order to communicate with the FIFO 13. However, the image upscaling device 10 can only provide upscale capability without downscale ability, which is unsatisfactory to the user.
Therefore, it is desirable to provide an image scaling device to mitigate and/or obviate the aforementioned problems.